As for the one year, last release was on 2018, Kotlin was announced as main Android language in May 2017.
Now re-read my comment.
The three years predating it was JetBrains trying to find a way to sell Kotlin adoption, then they went big and closed shop.
Now they are stuck with Kotlin being seen as an Android language for the most part, and Fleet isn't taking off.
Perhaps it’s different elsewhere, but here in Norway I’ve seen Kotlin used quite extensively in large backend codebases. It also comes up frequently in job postings—employers seem to actively ask for it when hiring.
https://trends.google.com/trends/explore?q=java,kotlin,scala...
https://senacor.blog/in-praise-of-kotlin-a-modern-programmin...
Most shops that use Kotlin on the backend also do Android development, as means to do core sharing between backend and Android, and there is the whole ART is not a JVM implementation anyway.
None of the companies that I wrote Kotlin for or that I applied to used Kotlin for code sharing between backend and Android. It seems as if you're making a lot of assumptions in this comment thread.
Can share more market research reports if you feel like, with similar numbers.
Also no idea how the links you posted are supposed to support your assertion that Kotlin is chosen due to code sharing considerations.
The links I posted, and others I can reach out for, support my assertions of 10% Kotlin market size in JVM deployments.
What you call my assertion, is my assumption about where those 10% are coming from.
We wanted the JVM for the JDBC ecosystem due to being a data tool, and Kotlin seemed like the "least bad" flavor.
No regrets.
I tried it for a few hours. I have no idea what I was supposed to notice.
Was the intent do be a new collaboration-first engine? Yes please.